The active astringent principles of cutch. are a tannin formerly known as catechu-tannic acid and a crystalline body namedcatechin. The value of cutch as a dyeing and tanning agent depends upon the amount of these two substances, while at the same time they are a measure of its suitability as a medicine.
{{smaller|According to Professor H. R. Proctor of Leeds, the following are the analyses of extracts from Acacia Catechu : —
| Tanning matter. | Non-tanning matter. | Insoluble. | Water. | |
|---|---|---|---|---|
| Dark Cutch | 58.9 | 1.0 | 19.1 | 12.0 |
| White cutch of kath | 72.2 | 5.8 | 6.8 | 14.2 |
| Yellow cutch, pegu, Burma | 69.2 | 8.0 | 10.4 | 12.4 |
Professor Proctor also forwarded some figures of recent analyses of extracts which were supposed to be derived from Acacia Catechu.
| Mark. | Tanning matter. | Non-tanning matter. | Insoluble. | Water. | Tanning on dried extract. |
|---|---|---|---|---|---|
| Drysdale | 42.2 | 25.6 | 07.6 | 24.6 | 55.8 |
| Salatiga | 30.8 | 29.7 | 02.2 | 37.3 | 49.1 |
| B.B. Flag I | 62.6 | 12.0 | 10.0 | 15.4 | 73.9 |
| B.B. Leurel II | 59.6 | 15.5 | 07.6 | 17.3 | 72.0 |
| B. Star 3 | 46.5 | 23.2 | 14.9 | 15.4 | 54.9 |
| 41 | 41.5 | 17.6 | 04.6 | 36.3 | 65.1 |
| 42 | 29.6 | 18.8 | 31.1 | 20.5 | 37.3 |
| Pegu | 30.0 | 35.4 | 00.7 | 24.9 | 39.9 |
| Assam | 46.4 | 34.3 | 02.7 | 16.6 | 55.6 |
| Ame | 45.7 | 19.8 | 15.8 | 18.7 | 56.2 |
(Agricultural Ledger, 1906— No. 3 pp. 39-41.)
448. A. ferruginea, D.C. h.f.b.i., ii. 295.
Syn: — Mimosa ferruginea, Roxb. 423.
Habitat : — Western Peninsula.
Vern— Khour (Nepal); Velvelam, sbirnai-velvel (Tam.) Anasandra, vuni or woanee (Tel.) ; Kaiger (Panch Mahals) Sou khair (Berar) ; Kar, khair (Gond.) ; Pandhra ; khair (Mar.) Teori khair (Bhil.) ; Bauni (Kan.)
Of the pods — Babûl-ki-sengriyán(H.) ; Kali-kikar-ki-phaliyan (Dec.) ; Velam-káygal, Karu-velam-kaygal, karu-vel-kaygal (Tam.) ; Nalla-tumma-káyalu, barbúramu-káyalu, tumma-chettu-káyalu (Tel.); Karu-vélakam-káya (Mal.); Kare-jáli-káyi, kare-gobbali-káyi (Can.); Bábul-sim, bábla-sim (Beng.) ; Kala- bábili-cha-phalli, Bábli Siring (Mah.); Kálobával-nu-singo (Guz).
